Vertical analysis of patients with late lower arch crowding

Abstract EN

Background: Because of many factors play a role in the developing of late lower arch crowding, therefore the objective of the current study is to do vertical analysis for subjects with late lower dental arch crowding.

The conducted study is the first attempt to do vertical analysis for Iraqi subjects with late lower arch crowding to see if there is a vertical discrepancy in such patients.

Subjects and methods: Eighty subjects were selected according to certain inclusion criteria from patients attending the Orthodontic Department in the College of Dentistry, Baghdad University, patients ranged between 18-25 years old.

The 80 patients were divided into two groups (crowding and normal), 40 patients each (20 males and 20 females).

A study cast of lower dental arch was obtained, and then Nance's space analysis made for each cast, Cephalometric radiographs were also taken for each patient involved in the current study and digitization was done to calculate nine vertical linear and twelve angular measurements.

Results: Most of linear measurements showed higher mean values in crowding than normal subjects except S-Go, Ar- Go, and PFH/AFH, also subjects with crowding had significantly higher (P<0.05) anterior facial height (ANS-Me) than normal subjects, and that difference occurred only in the lower part of the face, the Jaraback Ratio (PFH/AFH) was also low in crowding subjects, also higher mean values of LADH, UADH and UPDH in crowding group, may be due to compensatory over eruption of teeth as a result a bite opening occurred, indicating that patients with crowding have tendency toward posterior rotation.

Regarding the angular measurements, subjects (total males and females) with crowding had larger mean values than normal.

There were no interactions between total mean values of normal and crowding subjects for any outcome angular parameter, except four of the twelve angular measurements (SN-MP, Occ-MP, PP-MP, and sum S.A.G angles) showed an interaction, with females in both normal and crowding groups exhibited higher mean values than males.

Conclusions: Subjects with late lower arch crowding can have and/or affect on the vertical dimension, and the vertical discrepancy in late lower arch crowding should be considered during diagnosis and treatment plane of orthodontic cases, active treatment, and retention phase, in order to have stable end result in long term prognosis in orthodontics.